how two musical notes terrified an entire generation

Our experience of the world often involves hearing our environment before seeing it. Whether it’s the sound of something moving through nearby water, or the rustling of vegetation, our fear of the unseen is rooted in our survival instincts as a species.

Cinematic sound and music taps into these somewhat unsettling instincts – and this is exactly what director Steven Spielberg and composer John Williams achieved in the iconic 1975 thriller Jaws. The sound design and musical score work in tandem to confront the audience with a mysterious killer animal.

In what is arguably the film’s most iconic scene, featuring beach swimmers’ legs flailing underwater, the shark remains largely unseen – yet the sound perfectly conveys the threat at large.

Creating tension in a soundtrack

Film composers aim to create soundscapes that will profoundly move and influence their audience. And they express these intentions through the use of musical elements such as rhythm, harmony, tempo, form, dynamics, melody and texture.

In Jaws, the initial encounter with the shark opens innocently with the sound of an offshore buoy and its clanging bell. The scene is established both musically and atmospherically to evoke a sense of isolation for the two characters enjoying a late-night swim on an empty beach.

But once we hear the the low strings, followed by the central two-note motif played on a tuba, we know something sinister is afoot.

This compositional technique of alternating between two notes at an increasing speed has long been employed by composers, including by Antonín Dvořák in his 1893 work New World Symphony.

John Williams reportedly used six basses, eight cellos, four trombones and a tuba to create the blend of low frequencies that would go on to define his entire Jaws score.

The bass instruments emphasise the lower end of the musical frequency spectrum, evoking a dark timbre that conveys depth, power and intensity. String players can use various bowing techniques, such as staccato and marcato, to deliver dark and even menacing tones, especially in the lower registers.

Meanwhile, there is a marked absence of tonality in the repeating E–F notes, played with increasing speed on the tuba. Coupled with the intensifying dynamics in the instrumental blend, this accelerating two-note motif signals the looming danger before we even see it – tapping into our instinctive fear of the unknown.

The use of the two-note motif and lower-end orchestration characterises a composition style that aims to unsettle and disorientate the audience. Another example of this style can be heard in Bernard Herrmann’s car crash scene audio in North by Northwest (1959).

Similarly, in Sergei Prokofiev’s Scythian Suite, the opening of the second movement (Dance of the Pagan Gods) uses an alternating D#–E motif.

The elasticity of Williams’ motif allows the two notes to be played on different instruments throughout the soundtrack, exploring various timbral possibilities to induce a kaleidoscope of fear, panic and dread.

The psychology behind our response

What is it that makes the Jaws soundtrack so psychologically confronting, even without the visuals? Music scholars have various theories. Some suggest the two notes imitate the sound of human respiration, while others have proposed the theme evokes the heartbeat of a shark.

Williams explained his approach in an interview with the Los Angeles Times:

I fiddled around with the idea of creating something that was very … brainless […] Meaning something could be very repetitious, very visceral, and grab you in your gut, not in your brain. […] It could be something you could play very softly, which would indicate that the shark is far away when all you see is water. Brainless music that gets louder and gets closer to you, something is gonna swallow you up.

Williams plays with the audience’s emotions throughout the film’s score, culminating in the scene Man Against Beast – a celebration of thematic development and heightened orchestration.

The film’s iconic soundtrack has created a legacy that extends beyond the visual. And this suggests the score isn’t just a soundtrack – but a character in its own right.

By using music to reveal what is hidden, Williams creates an intense emotional experience rife with anticipation and tension. The score’s two-note motif showcases his genius – and serves as a sonic shorthand that has kept a generation behind the breakers of every beach.